Diffusion is the passive movement of any particle from an area of high concentration to an area of low concentration along the concentration gradient.
Answer: Exponential
Explanation:
The main requirement for the population of a species to grow is food. When there is food, a organisms that are born will be able to live longer because food will be able to sustain them.
This is what happened with humans during the Neolithic Revolution when we began farming.
The general trend is that the more food that is available, the higher the population growth. When these butterflies arrived and found no competition for food, their population would increase in the highest way possible which is exponentially because there would be plenty of food to go around.
